P75 comparison between 4% formalin instillation and purastat application for radiation proctopathy

Abstract

Introduction: Formalin therapy is an established method for the treatment of radiation proctopathy (RP). Emerging data suggests a potential role for Purastat application in the treatment of RP; however, no comparison to conventional treatment has been made to date. The aim of this study was to assess the safety and efficacy of Purastat for the treatment of RP compared to conventional treatment. Methods: consecutive patients with RP referred between January 2018 and December 2019 were treated with either conventional formalin or Purastat, based on endoscopist preference. Patients symptoms were scored with the subjective, objective management analysis (SOMA) scale, and the endoscopic severity of RP was graded by Zincola score. These measures were taken pre-treatment and prior to any subsequently planned treatments if clinically warranted, typically at 6-week intervals up to a maximum of 4 sessions. Results: of 17 patients (all male) referred for treatment, 11 patients underwent conventional Formalin instillation and 6 patients Purastat. Table 1 shows demographic and treatment outcomes. There was no statistical difference between the 2 groups in patient demographics, baseline symptom severity and Zincola score. Post-treatment protocol SOMA score reduction was significantly greater in the formalin group v Purastat group (8 to 1 v 8.2 to 4, p=0.01 respectively), and Zincola score reduction ( 4–2 v 4–3, p= 0.04 respectively). There was 1 case of mild anaphylaxis with facial flushing with Formalin, which settled with observation. [P75 Table 1 Demographic and treatment outcomes not included]. Conclusions: formalin instillation is still a cheap and effective treatment of RP. Although Purastat has a beneficial adverse event profile, its limited effect in this small cohort does not yet warrant widespread usage